Replacing water to get rid of CYA

[MarkC]

I like Poconos plastic sheet method.

[bbb]

xcapecod83 - duraleigh's questions are excellent ones. Also, is your pool plaster or vinyl liner? If it is a vinyl liner pool, my understanding is that you have to be extra careful to keep your pool at least 1/3 full in order to keep your liner in place. Also, what method did you use to test that your CYA is 150? Are you positive it is that high?

[xcapecod83]

xcapecod83 - duraleigh's questions are excellent ones. Also, is your pool plaster or vinyl liner? If it is a vinyl liner pool, my understanding is that you have to be extra careful to keep your pool at least 1/3 full in order to keep your liner in place. Also, what method did you use to test that your CYA is 150? Are you positive it is that high?

I'm using the CYA test in the Leslie's DPD test kit (the one where you add water until the black dot at the bottom of the cylinder disappears). I checked it twice.

[bbb]

I'm using the CYA test in the Leslie's DPD test kit (the one where you add water until the black dot at the bottom of the cylinder disappears). I checked it twice.

Great - I was hoping you were using the black dot test. I just wanted to make sure you were using the proper test, and not just a pool store printout or test strip, before going through all the effort of a drain/refill. As others on the post have said, if you get the CYA down between 50 and 100, you can certainly successfully run the pool (using the higher Cl amounts suggested in Ben's "best guess" table), so make your own judgement about the target level based on the amount of effort you want to put in, the cost and quality of your fill water, etc.

Good luck!

[grangerhj]

I have been battling an elevated CYA for the past month- found out it was elevated by chance- my pool store must not have tested for it because I never was told it was a problem. Reading of around 150. Have a fiberglass pool and was told by installer that I could not empty it more than 12 "- I have done that twice with very little inmprovement. I waqs swimming in the pool- which looks great by the way, I just have to keep using chlorine- am I in any danger using the pool?:

[cygnusecks]

Couldn't you simply use two hoses: one is siphoning water out while at the same time a different hose is adding new water? This wouldn't remove CYA as fast (and you'd waste more water) but this would avoid having to empty the pool at all...

I've never needed to drain so I'm just hypothesizing that this method would work.. wouldn't it?

[BillyBumbler]

So, if you shouldn't completely drain a pool because ground water might push it up, how do you resurface a pool when it's time?

[cwstnsko]

I believe one option is to dig a sump next to the pool and pump off ground water continuously during the refinishing process. In some areas, careful choice of the time of year to do the refurb can help.